1. Field of the Invention
This invention relates generally to the manufacturing of enclosures (e.g., housings, battery covers, etc.) for electronic devices, and more particularly to the manufacturing of metal enclosures for 3C (computers, communications, consumer electronics) devices. Even more particularly, the present invention relates to preventing a bimetallic enclosure from experiencing warp deformation when heated by a manufacturing process, for example an NMT (Nano Mold Technology) process.
2. Description of the Background Art
Currently, the demand for 3C products is becoming increasingly more dependent on aesthetics. As a result, more and more eye-catching effects and differentiating characteristics are being incorporated into the enclosure design of such products. For example, metal housings are the current trend in the 3C market.
Applicants have discovered that there are advantages to forming metal housings from bimetallic metal. One example of bimetallic material is sheet metal that is formed by cold rolling two sheets of different metals together to form a single two-ply sheet. As used herein, the term bimetallic is considered to also include materials having more than two layers formed of two or more different metals.
Although advantages exist, there are some problems that must be addressed in order to increase product yield. For example, bimetallic sheet metal is prone to warp when subjected to significant temperature changes, because the two metals have a different coefficients of thermal expansion (CTEs). As a result, bimetallic components are particularly vulnerable during manufacturing processes in which the shell is exposed to heating. For example, bimetallic shells can experience serious warp deformation after being released from an NMT mold and allowed to cool at room temperature.
What is needed, therefore, is a means for preventing warpage of bimetallic components during manufacturing. What is also needed is a means for preventing warpage of bimetallic components subjected to manufacturing processes involving heat. What is also needed is a means for preventing warpage of bimetallic components that are involved in molding processes. What is also needed is a means for improving the product quality and yield of manufacturing processes involving bimetallic components.